freshwater lakes, rivers & water catchment dams

Huia Dam

Duration: 1 week I Date: 2014

Background

Auckland city is the fastest growing city in New Zealand with numerous fresh water dams. As the city increases in size so does the demand for fresh water. Storage volume data, arising from lake level fluctuations and potential sediment build up, is key to the management of these assets.

Requirement

Watercare requires high resolution hydrographic surveys of the dams in order to provide accurate bathymetric data. These high resolution datasets are used for precise volume calculations and to support on going monitoring and management of the dams and associated infrastructure.

Challenges

The Waitakere ranges are renowned for pristine native forest and rugged topography. This can pose access and health and safety challenges when deploying surveying teams, equipment and vessels into inland water bodies. For each survey a rigid Health and Safety Plan is employed to help protect the people involved, the environment and the water quality. DML's experienced team of people, portable ruggedized equipment and custom built survey boats are ideal for remote and difficult to access areas.

Solution

DML undertook high resolution MBES surveys of the lakes as well as 3D Laser Scanning of the overflow channel and water tow. Gridded data sets were derived and provided to the Client enabling volume data of each dam to be calculated. DML also provided free software and 3D fly throughs of each dataset that allows Watercare to investigate their asset from all aspects to a very high level of detail.

Outcome

In each case the survey objectives were achieved and they were delivered on time and to budget.

DML has conducted other high resolution MBES surveys where 3D fly throughs have been created for Clients.